Liquid ejection apparatus and liquid ejection head

Abstract

A liquid ejection apparatus includes an energy generating element that generates energy for ejecting a liquid; a plurality of electroconductive protective films that are disposed so as to cover at least the energy generating element and that are in contact with the liquid; and an electrifying unit that is capable of electrifying the plurality of electroconductive protective films in such a way that surfaces of the electroconductive protective films in contact with the liquid serve as anodes.

What is claimed is: 
     
       1. A liquid ejection apparatus comprising:
 an energy generating element that generates energy for ejecting a liquid; 
 an insulation film covering the energy generating element; 
 a plurality of electroconductive protective films that are disposed so as to cover the energy generating element and the insulation film, and that are in contact with the liquid; and 
 an electrifying unit that is capable of electrifying the plurality of electroconductive protective films in such a way that surfaces of the electroconductive protective films in contact with the liquid serve as anodes. 
 
     
     
       2. The liquid ejection apparatus according to  claim 1 , comprising:
 a liquid ejection head including a plurality of recording element substrates each including the energy generating element and the electroconductive protective films. 
 
     
     
       3. The liquid ejection apparatus according to  claim 2 ,
 wherein the electrifying unit is capable of individually electrifying the electroconductive protective films of the plurality of recording element substrates. 
 
     
     
       4. The liquid ejection apparatus according to  claim 2 ,
 wherein the electrifying unit is electrically connected to the electroconductive protective films of the plurality of recording element substrates and is capable of selecting at least one of the electroconductive protective films to be electrified. 
 
     
     
       5. The liquid ejection apparatus according to  claim 2 ,
 wherein the electrifying unit is capable of simultaneously electrifying the electroconductive protective films of the plurality of recording element substrates. 
 
     
     
       6. The liquid ejection apparatus according to  claim 1 , further comprising:
 a detection unit that detects anodization of the electroconductive protective films. 
 
     
     
       7. The liquid ejection apparatus according to  claim 6 ,
 wherein in a case where the anodization of the electroconductive protective film is detected by the detection unit, the electrifying unit electrifies to anodize an electroconductive protective film not being anodized. 
 
     
     
       8. A liquid ejection head comprising:
 a plurality of recording element substrates each including:
 a member having an ejection orifice from which a liquid is ejected, and 
 a substrate including:
 an energy generating element that generates energy for ejecting the liquid, 
 an insulation film covering the energy generating element, and 
 an electroconductive protective film that is disposed so as to cover the energy generating element and the insulation film; and 
 
 
 an electrifying unit that is capable of electrifying the electroconductive protective films of the plurality of recording element substrates in such a way that surfaces of the electroconductive protective films in contact with the liquid serve as anodes. 
 
     
     
       9. The liquid ejection head according to  claim 8 ,
 wherein the electrifying unit is provided in each of the recording element substrates. 
 
     
     
       10. The liquid ejection head according to  claim 8 ,
 wherein the electrifying unit electrifies the electroconductive protective films by using an electric power source for driving the energy generating elements. 
 
     
     
       11. The liquid ejection head according to  claim 8 ,
 wherein the electrifying unit electrifies the electroconductive protective films by receiving supply of electric power that is controlled by using a signal for driving the energy generating elements. 
 
     
     
       12. The liquid ejection head according to  claim 8 , further comprising a detection unit that detects anodization of the electroconductive protective films,
 wherein in a case where the anodization of the electroconductive protective film is detected by the detection unit, the electrifying unit electrifies to anodize an electroconductive protective film not being anodized. 
 
     
     
       13. The liquid ejection head according to  claim 8 ,
 wherein the protective film includes tantalum. 
 
     
     
       14. A liquid ejection head comprising:
 a first recording element substrate and a second recording element substrate each including:
 an energy generating element that generates energy for ejecting a liquid, 
 an insulation film covering the energy generating element, and 
 an electroconductive protective film that is disposed so as to cover the energy generating element and the insulation film; and 
 
 an electrifying unit that is capable of electrifying the electroconductive protective films of the first and second recording element substrates in such a way that surfaces of the electroconductive protective films in contact with the liquid serve as anodes. 
 
     
     
       15. The liquid ejection head according to  claim 14 ,
 wherein the electrifying unit is provided in the first recording element substrate. 
 
     
     
       16. The liquid ejection head according to  claim 14 ,
 wherein the electrifying unit electrifies the electroconductive protective films by using an electric power source for driving the energy generating elements. 
 
     
     
       17. The liquid ejection head according to  claim 14 ,
 wherein the electrifying unit electrifies the electroconductive protective films by receiving supply of electric power that is controlled by using a signal for driving the energy generating elements. 
 
     
     
       18. The liquid ejection head according to  claim 14 ,
 wherein in a case where anodization of the electroconductive protective film of the first recording element substrate is detected by a detection unit that detects the anodization of the electroconductive protective film, the electrifying unit electrifies to anodize an electroconductive protective film of the second recording element substrate not being anodized. 
 
     
     
       19. The liquid ejection head according to  claim 14 ,
 wherein the protective film includes tantalum.